Fast, Reliable Bathroom Remodeling Across San Antonio Heights
Bathroom remodeling in San Antonio Heights runs $18,000 – $45,000 for a typical full gut-and-rebuild, with smaller refreshes starting around $9,000 and larger primary-suite builds reaching $65,000 or more. The number that moves most on these foothill ranch homes is what’s hiding behind the tile. We’ll come out to your property on the Euclid Avenue corridor, off 24th Street, or anywhere in the 91784 ZIP, open the walls, and show you exactly what you’re working with before you commit a dollar. Call (855) 949-1913 for a free estimate.
Why Sunstone ADU Builders Is San Antonio Heights’s Preferred Bathroom Remodeling Company
San Antonio Heights homes are different from what you’ll find ten minutes down the hill in Upland. These are mid-century and older custom ranch houses on half-acre-plus lots, built when building codes were looser and waterproofing standards were nothing like today’s. That means the bathroom remodel you’re planning will almost certainly turn up something behind the walls, and how your contractor handles that discovery determines whether the job finishes on budget or spirals.
Our crews work in San Antonio Heights regularly, and we know the housing stock here. We know what a 1960s hall bath off Euclid Avenue typically hides. We know how San Bernardino County inspectors review these jobs, because every permit in this unincorporated foothill community runs through the county, not a city building department. Homeowners in Upland or Rancho Cucamonga don’t deal with that extra review layer. You do, and we plan for it from day one.
Our Bathroom Remodeling team handles everything from the initial demolition to the final trim, and because Sunstone ADU Builders specializes in accessory dwelling units, we’re particularly good at bathroom build-outs inside detached guest houses and granny flats. That’s not a side service for us. It’s core work.
Nate Holloway, who leads Sunstone ADU Builders, built this company around the idea that homeowners should never have to coordinate a structure contractor and a separate interior finisher. When you remodel a bathroom with us in San Antonio Heights, you get one contract, one schedule, and one person accountable for the result.
Our Bathroom Remodeling Services in San Antonio Heights
Full Bathroom Remodeling
We gut and rebuild bathrooms in the custom ranch homes that define San Antonio Heights. That means removing everything to the studs, fixing whatever the county inspection flags, and rebuilding with properly sloped waterproofing, modern ventilation, and materials that hold up under the foothill sun and cold winter nights. On a half-acre parcel off 24th Street, we recently opened a 1960s hall bath and found the shower pan had been leaking into undersized, dry-rotted framing plus ungrounded cloth wiring feeding the vanity. We stopped, documented the damage with photos, priced the reframing and a GFCI circuit in writing, and got signed approval before any repair, then rebuilt with James Hardie backer and a properly sloped pan so the county inspection cleared on the first pass.

Detached Guest House and Granny Flat Bathroom Build-Outs
San Antonio Heights has more detached guest houses, barns, and outbuildings than almost any community in the western Inland Empire, and many of them need a bathroom added or completely redone before they’re usable. Because Sunstone ADU Builders is an authorized builder for prefab brands including Cover, Dvele, and Mighty Buildings, we can handle the structure and the bathroom interior under one roof. You don’t call a second contractor to finish what the first one started. We bring the unit to rental-ready condition, or build the granny flat bathroom from the ground up on an existing slab.

Pre-Remodel Inspection and Open-Wall Damage Assessment
This is the service that saves San Antonio Heights homeowners the most money, and it’s the one nobody else in the area emphasizes. Before you commit to a remodel budget, we open a small section of wall or ceiling and look at what’s actually behind the tile. In these mid-century foothill homes, that often means finding a shower pan with no sloped waterproofing layer, or subfloor rot under old tile, or cloth wiring that hasn’t been code-compliant in fifty years. We write our findings into a line-item report with photos, so your budget is based on reality, not hope.

Bathroom Finishing for ADU Interiors
When we build a detached ADU in San Antonio Heights for a rental unit or a family member, the bathroom is typically part of the same scope. We handle waterproofing, fixtures, tile, ventilation, and all county-required inspections as part of the ADU build. Since San Antonio Heights sits in a high-fire-severity foothill zone, we also pay attention to materials and placement that keep the entire structure compliant with ignition-resistant construction standards where they apply, even on an interior bathroom project.

What happens when you call
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A real person answersNo phone trees — you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in San Antonio Heights
Our work in San Antonio Heights regularly involves the prefab ADU platforms we’re authorized to build and install: Cover, Dvele, Mighty Buildings, and Boxabl among them. When we finish a bathroom inside one of these units, we’re working with the manufacturer’s specified rough-ins and clearances, not guessing. For traditional stick-built remodels on your main house, we specify James Hardie fiber cement siding on any exterior-facing bathroom walls, since the foothill climate demands siding that won’t warp under UV exposure and holds up during Santa Ana wind events. Whatever the structure, we bring the right materials for this specific location.
Common Bathroom Remodeling Problems We See in San Antonio Heights Homes
- Shower pans without a sloped waterproofing layer. Mid-century builders in the foothills often set tile directly on a flat mortar bed with no waterproof membrane. By the time we open it, the framing behind it is usually compromised, and the county inspection won’t pass until it’s corrected.
- Ungrounded or cloth-insulated wiring behind vanity walls. A 1960s ranch house off Euclid Avenue frequently still has the original two-wire electrical. Once walls are open, San Bernardino County requires upgrading to code, which means adding GFCI protection and often a new circuit, a cost no homeowner budgets for until we show them the wire.
- Subfloor and joist rot hidden under old tile. Decades of slow leaks from tubs and toilets in these foothill homes leave framing that looks fine from above and crumbles when you poke it. The county’s framing inspection will not pass until the damaged section is replaced and documented.
- Ventilation inadequate for foothill temperature swings. Hot summer sun exposure at this elevation combined with cold winter nights means moisture lingers in poorly vented baths. We see mold behind mirrors and under vanities in San Antonio Heights far more often than in tract homes below the hill, because the original exhaust fans were undersized or vented into the attic instead of outside.
Pricing for Bathroom Remodeling in San Antonio Heights, CA
A guest bath refresh in San Antonio Heights, with new fixtures, vanity, flooring, and paint, runs $9,000 – $16,000. A full hall bath gut-and-rebuild on a mid-century ranch typically lands between $18,000 and $34,000, depending on what the open-wall inspection turns up. A primary suite bathroom with a walk-in shower, custom tile, and upgraded ventilation runs $38,000 – $65,000 here. Detached guest house bathroom build-outs in the 91784 ZIP range from $15,000 for a compact 5×8 bath to $30,000 or more for a full bath with laundry hookups. The county permit corrections, when wiring or framing upgrades are required, typically add $2,500 – $8,000 depending on scope, and we price those as written allowances in the contract so you’re never surprised at the end. Call (855) 949-1913 to schedule your free estimate, and we’ll give you a line-item price for your specific house.
We Also Serve Cities Near San Antonio Heights
Beyond Bathroom Remodeling in San Antonio Heights, our crews work throughout the surrounding foothill and valley communities. You’ll find us on bathroom remodels in Upland, Claremont, Rancho Cucamonga, and Montclair. If your home sits near the San Antonio Heights boundary but has a different postal address, call us anyway. We know the county review process and the local housing stock up and down the hill.
Serving San Antonio Heights, CA — Our Local Coverage Area
We’re based in the San Antonio Heights area and know this community well. Use the map below to see our service coverage — if you’re nearby, we can almost certainly help.
FAQs – Bathroom Remodeling in San Antonio Heights
San Antonio Heights is unincorporated San Bernardino County, so every bathroom remodel permit goes through the county’s building and safety division, not a city building department. That adds a county-level plan review and inspection cycle that incorporated cities like Upland or Claremont don’t impose. In practice, it means the open-wall inspection is stricter about wiring and framing corrections, and the timeline runs a few days to a couple of weeks longer. We handle the county submittal and inspections for you, and we write the schedule with that review time already factored in. Call (855) 949-1913 for a free estimate.
We stop work, photograph everything, and give you a written change order with the exact price and scope of the repair before we touch anything else. You decide. You approve the number, or we adjust the plan. We never start a repair without signed approval, and we build allowances into the original contract for the most common open-wall surprises in San Antonio Heights homes, so the number doesn’t blindside you. This is the single biggest reason our quotes move, and it’s exactly why we insist on an inspection before the contract is final.
It can, though less directly than it affects an ADU structure. San Antonio Heights sits in a high-fire-severity zone, so exterior-facing bathroom walls, ventilation penetrations, and any new exterior siding are reviewed for ignition-resistant materials and ember intrusion. If your remodel adds a new exhaust fan or window, the county will check the penetration seals. We use James Hardie fiber cement on exterior walls and proper ember-rated vents so your remodel passes without a correction cycle.
Because the original construction rarely matches what’s behind the walls. Mid-century ranch houses in the 91784 ZIP were built before modern waterproofing, GFCI requirements, and ventilation standards. Once we open the walls, the county requires bringing exposed wiring and framing up to current code, and failed shower pans or rotted subfloors have to be replaced before the inspection will pass. We structure our quotes with explicit allowances for these corrections, priced in ranges, so the final number reflects what your specific house actually needs, not a generic estimate. Call (855) 949-1913 for an exact quote.
Yes, and this is work we do throughout San Antonio Heights, where detached garages, barns, and outbuildings are common on the larger foothill parcels. We assess the existing structure for foundation, framing, and utility access, then build the bathroom to ADU code with county inspections at each step. If the outbuilding needs structural work before it can hold a bathroom, we handle that under the same contract. No second contractor, no finger-pointing between trades. Call (855) 949-1913 to schedule a free walkthrough of your outbuilding.
Call us today at (855) 949-1913 for honest answers and a line-item estimate. We serve San Antonio Heights and the neighboring foothill communities, and we’ll walk your property, open what needs opening, and give you a real number before you sign anything.
Written by Nate Holloway, Owner at Sunstone ADU Builders, serving San Antonio Heights and the western Inland Empire.